As American involvement deepened in Vietnam-what obstacles did U. S. troops encounter that proved difficult to overcome?

During what century did muhammad recieve his first revelation from god

Describe two observations that galileo was the first to make with his telescope.

Which statement about submarine use in world war i is true? the allies never found a way to counter german submarine warfare. germany’s use of submarines affected the united states’ decision to enter the war. only the germans used submarines in world war i.